Abstract: A drive device for a pair of welding tongs having a pair of limbs, is arranged between the adjusting ends of the limbs, located opposite to the welding electrodes, for adjusting between a welding position and a standby position. In order to reduce its length, provide continuous control and monitoring, simplify the device and reduce noise, the drive device is provided with an electric motor-driven screw-thread drive with a rotating nut and a rotating spindle which is axially displaceable between an extended and a return position, the spindle being connected to an adjusting end of the limb. The drive device can be used as a main drive for a pair of welding tongs for the positioning of the limbs, or can be used as a secondary drive, for setting of a stopping position of the pair of welding tongs.

Abstract: A method for open or closed-loop control of welding tong movement utilizes a welding tong drive having a primary and a secondary drive device. The primary drive device moves two welding tong limbs with welding electrodes toward a welding object from opposite sides. The welding tong limbs press onto the welding object with a predetermined compressive force. During actuation, the secondary drive device varies a spatial orientation of the welding tongs. In order to contact the welding object in a controlled manner, and to reliably acquire any deviations from specified spatial points during contacting, the welding tongs first approach a spatial point relative to the welding object. The welding tong limbs are held in a fixed spatial orientation during the approach. The secondary drive device is actuated until a welding tong limb contacts the welding object. The primary drive device then closes the welding tong limbs.